Kristen Stewart's on-screen rival for Robert Pattinson has been cast. MyAnna Buring will play Tanya, with whom Pattinson Edward Cullen shared a past. MyAnna Buring will join the Twilight Saga cast as they film the two-part finale Breaking Dawn.

The casting was announced via TWILIGHT's official Twitter page.

Buring's character Tanya is part of the Denali coven whose members will play pivotal roles as the Cullens clashes with the Volturi in Forks.

Other actors who had been cast as the Denali coven vampires were Christian Camargo and Mia Maestro as Eleazar and Carmen; and Casey LaBow as Kate. Maggie Grace had been earlier announced to play Irina, the vampires who tells on the Cullen coven for the alleged creation of child vampire.

Breaking Dawn: Part 1 is scheduled to open Nov. 18, 2011.